1. Field of the Invention
The present invention relates to a cable modem including filtering based on a frequency band in the cable modem and, more particularly, to a cable modem including filtering based on a frequency band in the cable modem in which an upstream signal is transmitted via respective different Hybrid Fiber Coaxial (HFC) transmission paths embedded in the cable modem or a cable Set Top Box (STB).
2. Description of the Related Art
A cable modem transmits an upstream signal to a Cable Modem Termination System (CMTS) and receives a downstream signal from the CMTS over an HFC network.
A cable modem or a cable STB transmits and receives data and a video signal using the HFC network. The performance of the entire HFC network depends on communication between the CMTS/head end equipment and the cable modem/cable STB. An upstream signal transmitted by the cable modem or the cable STB plays the most important role.
The following patents each discloses features in common with the present invention but do not teach or suggest the inventive features specifically recited in the present application: U.S. patent application Ser. No. 2003/0012271 to McReynolds et al., entitled MULTI-MODE BI-DIRECTIONAL COMMUNICATIONS DEVICE INCLUDING A DIPLEXER HAVING SWITCHABLE LOWPASS FILTERS, published on Jan. 16, 2003; U.S. patent application Ser. No. 2002/0178454 to Antoine et al., entitled BROADCAST TELEVISION AND SATELLITE SIGNAL SWITCHING SYSTEM AND METHOD FOR TELEPHONY SIGNAL INSERTION, published on Nov. 28, 2002; U.S. patent application Ser. No. 2002/0023273 to Song, entitled APPARATUS FOR PROVIDING A MULTIPLE INTERNET CONNECTION SERVICE USING A HYBRID FIBER COAXIAL CABLE NETWORK, published on Feb. 21, 2002; U.S. patent application Ser. No. 2003/0022631 to Rhodes et al., entitled MULTI-MODE BIDIRECTIONAL COMMUNICATIONS DEVICE INCLUDING A DIPLEXER HAVING A SWITCHABLE NOTCH FILTER, published on Jan. 30, 2003; U.S. patent application Ser. No. 2002/0176524 to Popper et al., entitled INGRESS NOISE REDUCTION IN A DIGITAL RECEIVER, published on Nov. 28, 2002; U.S. patent application Ser. No. 2002/0049038 to Sorrells et al., entitled WIRELESS AND WIRED CABLE MODEM APPLICATIONS OF UNIVERSAL FREQUENCY TRANSLATION TECHNOLOGY, published on Apr. 25, 2002; U.S. patent application Ser. No. 2003/0033608 to Chang et al., entitled BTI RF MODULE WITH FILTERING, published on Feb. 13, 2003; U.S. patent application Ser. No. 2003/0046706 to Rakib, entitled ACTIVE CABLE MODEM OUTSIDE CUSTOMER PREMISES SERVICING MULTIPLE CUSTOMER PREMISES, published on Mar. 6, 2003; U.S. patent application Ser. No. 2003/0208775 to Roberts et al., entitled SYSTEM, METHOD AND APPARATUS FOR COORDINATION OF CHANNEL QUALITY ASSESSMENT AND INGRESS FILTERING IN CABLE MODEM SYSTEMS, published on Nov. 6, 2003; U.S. patent application Ser. No. 2003/0066088 to Jung, entitled BIDIRECTIONAL TRUNK AMPLIFIER AND CABLE MODEM FOR CABLE HYBRID FIBER AND COAX NETWORK WHICH UTILIZES AN UPSTREAM PILOT SIGNAL, published on Apr. 3, 2003.